S tate Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Environ Geochem Health. 2013 Dec;35(6):801-9. doi: 10.1007/s10653-013-9536-9. Epub 2013 May 24.
Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4-75.1 %) for N and 76.3 % (62.0-98.4 %) for P. The CWs retained about 1,278 kg N ha(-1) year(-1) and 121 kg P ha(-1) year(-1). There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt "zero-drainage" water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha(-1) year(-1) and 5.4 kg P ha(-1) year(-1). The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year(-1) and 151 kg P year(-1), which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system.
人工湿地（CWs）已被有效用于去除非点源中的氮（N）和磷（P）。然而，一些 CWs 的流出物仍然具有高浓度的 N 和 P，仍然是污染源。广泛分布的稻田可以被利用来缓解这一问题。我们是第一个在全规模范围内研究三级 CWs 与湿地稻田组合系统以去除农村非点源无管制的 N 和 P 的人。CWs 的去除效率（REs）达到了 57.3%（37.4-75.1%）的 N 和 76.3%（62.0-98.4%）的 P。CWs 保留了约 1278 kg N ha(-1) year(-1) 和 121 kg P ha(-1) year(-1)。N 和 P 的 REs 有明显的季节性变化，并且在 CWs 的不同处理组件中 REs 也不同。根据当地的降雨预报和作物生长的生理需水情况，湿地稻田采用“零排水”水管理，其去除率达到了 93.2 kg N ha(-1) year(-1)和 5.4 kg P ha(-1) year(-1)。水稻季比小麦季更有潜力去除 N 和 P。整个组合系统（0.56 公顷 CWs 和 5.5 公顷湿地稻田）去除了 1790 kg N year(-1)和 151 kg P year(-1)，高于 CWs 单独运行的去除量。然而，还需要另外 4.7 公顷的稻田才能完全去除 CWs 流出物中的 N 和 P。CWs 和稻田的组合被证明是一种更有效的养分去除系统。
